The present invention generally relates to a flow cell apparatus and, in particular, relates to such an apparatus for equilibrating the temperature of a fluid passing therethrough.
Sample cells are available in a variety of shapes, sizes and configurations. In addition, heat exchangers for use therewith are also known. The primary purpose of previous heat exchangers is to merely remove thermal energy from the sample cell. Very often such a heat exchanger functions by transferring thermal energy to a moving working fluid, which can, of course, be a gas, and which, subsequently, carries the transferred thermal energy away from its source.
However, in many applications, the simple removal of thermal energy is not quite as important as is the ability to equilibrate, or stabilize, the temperature of a flowing fluid on both sides of a device through which the fluid is passed.
One device where such equilibration is highly desirable is the flow cell of a liquid chromatography system. In a liquid chromatography system, the eluate of the separating column exits at a rather elevated temperature and is conveyed, via a relatively short connecting conduit, to a measuring flow cell. Often, a measuring light beam is passed through the flow cell and the intensity reduction of the light beam during its passage through the cell is a measure of the absorbance of the fluid passing therethrough. Frequently, if the temperature of the eluate of the separating column is significantly different from the flow cell, even if such a temperature difference may be an acceptable consequence of a particular separation, unacceptable noise may nevertheless result in the detection mechanism of the chromatograph. Hence, it is often desirable to stabilize the temperature of an eluate from a separating column. However, if such a temperature stabilization is performed it is quite important to maintain that temperature at a constant level.
Conventionally, this result is accomplished by employing known heat exchanging mechanisms. For example, by providing a water jacket about the sample cell and/or the inlet conduit. The desired temperature is then obtained by circulating a coolant through the jacket at a selected flow rate. Such an arrangement requires careful monitoring and controlling of both the coolant temperature and the flow rate. The provision of such monitoring and controlling usually requires considerable expenditures and often complex mechanisms.
SUMMARY OF THE INVENTION
Accordingly, it is one object of the present invention to provide an apparatus for equilibriating the temperature of a fluid passing through a flow cell.
This object is accomplished, at least in part, by providing a flow cell and thermal communication between the inlet conduit and the outlet fluid thereof.
Other objects and advantages will become apparent to those skilled in the art from the following detailed description read in conjunction with the appended claims and the drawing attached hereto.